This invention relates to the use of alpha olefin/maleic anhydride terpolymers in cleaning compositions. More particularly, this invention relates to the use of these terpolymers in conjunction with anionic surfactants, such as ammonium lauryl sulfate and ammonium lauryl ether sulfate, in hair shampoos, hand or skin cleaners and other cleaning compositions.
The use of anionic surfactants or detergents in skin and hair cleaning compositions is well known. Most of the major national brand liquid hand soaps contain sodium C.sub.14-16 olefin sulfonate or sodium lauryl sulfate as the major anionic surfactant. Additionally, several major national brand shampoos contain ammonium lauryl sulfate, ammonium lauryl ether sulfate, or mixtures thereof. It is well-known and universally accepted that these compositions are irritating to the skin and eyes under many conditions of use. Nevertheless, anionic surfactants continue to be frequently used in cleaning compositions because of their superior foaming characteristics. These characteristics exist even when the anionic surfactants are present in relatively dilute amounts. It has long been desired to reduce or eliminate the irritability of such cleaning compositions without compromising their superior cleaning and foaming properties.
The alpha olefin/maleic anhydride terpolymers employed in the compositions of this invention are disclosed in Reexamination Certificate No. B1 4,358,573. These compounds are terpolymers because they are composed of two different alpha olefin monomers (herein described as a lower 1-alkene and a higher 1-alkene) and a maleic anhydride monomer. These terpolymers are described as waxy materials having a low viscosity, suitable for such end uses as mold release agents, slip agents and additives to floor polishes. This patent, however, does not disclose or suggest the use of these terpolymers in skin and hair cleaning compositions. Additionally, these terpolymers are generally poor foam producers when employed alone.
Various efforts to reduce the irritation of cleaning compositions, yet maintain the desired foaming properties, have been proposed. For example, certain commercial formulations eliminate the pain of eye irritation, not by the use of non-irritating ingredients, but by the addition of an ingredient to anesthetize the eyes so that the irritation caused to them is not transmitted to the pain centers. Unfortunately, the subject continues to suffer eye irritation.
An article by T. Schoenberg entitled "Formulating Mild Skin Cleaners", Soap/Cosmetics/Chemical Specialties, May 1983, p. 33, discloses various formulations of mild skin cleaners. Schoenberg recommends the use of sulfosuccinate half-esters as partial replacements of anionic surfactants, such as sodium lauryl sulfate, for reducing irritation. However, such replacement compounds are said to prevent significant irritation only when they are substituted in amounts on the order of 75%, which raises the cost of such cleansers to unduly high levels and reduces their foaming characteristics, significantly.
Accordingly, a need exists for cleaning compositions which are mild (non-irritating), yet have sufficient foaming for cleaning ability.